Contour Enthusiasts Group Archives Forums Modifications Duratec Performance Some interesting info on Header Wrap

Good information but you must remember that most are using stock motors and the temps are not going to run that high for these people. This is also for Naturally aspirated engines not turbos. I noticed what I believe is improved boost response when using header wrap vs without. I also didn't coat every inch, I did the majority of it to keep from roasting all my wiring, radiator fans and AC hoses. I run wrap from the collection point on my crossover pipe up to the turbo and back down based on the proximity to components.

Some people have been running wrapped headers a long time too. So I don't know what the right answer is, guess it depends on your goals. I'd prefer to run heat shields rather than wrap but I've no room in certain areas.

Did you know that under the stock y-pipe heat shield there is a foam or wrap injected next to the pipes? Yep, the whole pipe under the shielding is essentialy wrapped. Also, the precat champers on the stock manifolds are double walled which would spell death for any metal if breathing were the only issue at stake, especailly since that is only inches from the exhaust port.